Field of the Invention
The present invention relates to a water recovery device to recover water from exhaust gas including water vapor.
Description of the Related Art
Society as a whole has been recently becoming more and more demanding in reducing of carbon-dioxide, and in response to such a demand, the development of various techniques has been tried in the technical fields to produce power by combusting fuel (e.g., for engines of automobiles) so as to improve thermal efficiency (power) of a power engine.
One of the contemplated methods to improve the thermal efficiency of a gasoline engine is to increase the compression ratio during compression of mixture gas of evaporated gasoline and air. Actually according to this method, a larger explosion power (expansion power) can be obtained when this compressed mixture gas is ignited, meaning that a larger power can be produced from the same amount of fuel.
It is known in general, however, that when the compression ratio is high, abnormal combustion likely occurs, in which impurities in the gasoline engine, such as carbon, trigger ignition prior to the ignition by an ignition device.
As one measure to avoid such a problem, a method is proposed to inject water beforehand to add water to the mixture gas of evaporated gasoline and air (see Non Patent Document 1, for example). In this method, the added water can control abnormal combustion because it suppresses drying in the gasoline engine. Water to be injected for addition is stored in a container, such as a tank, and is used little by little along with the operation of the gasoline engine, and when the amount of water in the container becomes low, water is fed from the outside in the same way as gasoline as fuel.